US2723503A - Grinding machine - Google Patents

Description

Nov. 15,1955

8. S. MADER GRINDING MACHINE Filed Nov. 8, 1952 8 Sheets-Sheet 1 IN VEN TOR. 5TWAET 5'. MAUEE Nov. 15, 1955 Filed Nov. 8, 1952 S. S. MADER GRINDING MACHINE 8 Sheets-Sheet 2 INVENTOR. Bram/a7- 5. MA DER BY WM) @010.

Nov. 15, 1955 s. s. MADER GRINDING MACHINE 8 Sheets-Sheet 3 INVENTOR. T 5'. MA DER m M T 5 Filed Nov. 8, 1952 Nov. 15, 1955 s. s. MADER 2,723,503

GRINDING MACHINE Filed Nov. 8, 1952 8 Sheets-Sheet 5 STEWART .5. MA 05/? Nov. 15, 1955 s. s. MADER 2,723,503

GRINDING MACHINE Filed NOV. 8, 1952 8 Sheets-Sheet 6 INVENTOR. 5 TEWAE'T 5. MAUER Mum.

( Nov. 15, 1955 s. s. MADER 2,723,503

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S'TEWA ET 5. MADE}? BY Mm-E51 Nov. 15, 1955 s. s. MADER 2,723,503

GRINDING MACHINE Filed Nov. 8, 1952 V 8 Sheets-Sheet 8 IN V EN TOR.

BY ETEWAET 57 MA 05/? Main United States Patent Ofifice 2,723,503 Patented Nov. 15, 1955 GRINDING MACHINE Stewart S. Mader, Worcester, Mass., assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts The invention relates to grinding machines and more particularly to a double head crankpin grinding machine.

One object of the invention is to provide a simple and thoroughly practical crankpin grinding machine. Another object is to provide a two-speed-fiuid motor actuated table traversing mechanism. Another object is to provide a table indexing and positioning mechanism for precisely positioning successive crankpins to be ground into operative relation with the grinding wheel. Another object of the invention is to provide a table positioning mechanism which is arranged to slow down the normal movement of the table just before the table reaches an indexed position. Another object is to provide a plunger and notched locating bar for positioning thework table in which movement of the plunger serves to slow down the rapid table movement as a notch approaches the plunger and to stop the table movement as the plunger moves into engagement with the notch.

Another object is to provide an interlock between the table traversing and the wheel forwarding mechanism so that the table traversing mechanism is rendered inoperative except when the wheel slide is in a rearward or inoperative position. Another object of the invention is to provide on electrical control apparatus actuated by and in timed relation with the wheel feeding mechanism automatically to advance the steady rest shoes into supporting engagement with a crankpin being ground when steady rest, showing the rest in a lowered or inoperative position;

Fig. 8 is a fragmentary vertical sectional view, taken approximately on the line 8-8 of Fig. 6, through the work steady rest;

Fig. 9 is a fragmentary front elevation, on the enlarged scale, of the work steady rest;

Fig. 10 is a vertical sectional View, on an enlarged scale, taken approximately on the line 10-10 of Fig. 6, through the steady rest actuated mechanism; and

Fig. 11 is a combined electric and hydraulic diagram of the actuating mechanisms and the controls therefor.

A double head crankpin grinding machine has been illustrated in the drawings comprising a base 10 which serves as a support for a longitudinally traversable work table 11. The base 10 is provided with a longitudinally extending fiat way 12 and a parallel V-way 13 upon which the table 11 slides. The table 11 in turn supports a swivel table 14 having a pair of spaced aligned work heads 15 and 16 adjustably mounted thereon. The work heads 15 and 16 support a pair of pot chucks 17 and 18 respectively for supporting and synchronously rotating the opposite ends of a crankshaft during a grinding operation. The work heads 15 and 16 are provided with mating surfaces which mate with the upper surface of the swivel table 14 so that the heads may be adjusted lonthe rtae of infeed of the grinding wheel is changed to a sized feed. A further object is to provide a control valve actuated by movement of the table index plunger to control the rate of exhaust of fluid from the table traversing motor to facilitate a slow-down and stopping of the table before and when the plunger moves into engagement with a notch in the table locating bar. Other objects will be in part obvious or in part pointed out hereinafter.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. 1 is a front elevation of the improved crankpin grinding machine;

Fig. 2 is a vertical sectional view, on an enlarged scale,

22 of Fig. 1, through gitudinally on the swivel table 14 and clamped thereon in the desired adjusted position.

The work head 15 (Fig. 3) is provided with a rotatable spindle 20 journalled in a pair of spaced anti-friction bearings 21 and 22. A driving sprocket 23 is keyed onto the spindle 20 and is connected by a cog belt 24 with a sprocket 25.

The work head 16 is provided with a work spindle 30 which is journalled in spaced anti-friction bearings 31 and 32. A driving sprocket 33 is keyed onto the spindle 30 and is connected by a cog driving belt 34 with a sprocket 35.

It is desirable to rotate the work spindles 20 and 30 synchronously to drive the opposite ends of a crankshaft supported in the pot chucks 17 and 18 respectively. This driving mechanism comprises a tubular drive shaft 36. The left hand end of the shaft 36 is slidably keyed within a rotatable sleeve 37. The sleeve 37 is journalled in spaced anti-friction bearings 38 and 39 which are supported within work head 15. The right hand end of the shaft 36 is slidably keyed within a rotatable sleeve 40 which is journalled in spaced anti-friction bearings 41 and 42 supported within the work head 16.

A suitable driving mechanism is provided for rotating the tubular drive shaft 36 comprising a frame 45 mounted on the upper surface of the swivel table 14. A motor 46 is mounted on the frame 45 and is drivingly connected by multiple V-belts 47 with a multiple V-grooved pulley 48. The pulley 48 is keyed onto a rotatable shaft 49 which is journalled in spaced anti-friction bearings 50 and 51. The bearings 50 and 51 are fixedly supported within Fig. 4 is a fragmentary vertical sectional view, on an t the frame 45. A sprocket 52 is keyed onto the shaft 49 and is connected by a cog belt 53 with a sprocket 54 which is fixedly mounted on the left hand end of a rotatable shaft 55 (Fig. 3). The left hand end of the shaft 55 is journalled in an antifriction bearing 56 carried by the frame 45. The shaft 55 extends within the central aperture of the tubular drive shaft 36 to a point substantially midway'between the work heads 15 and 16. The right hand end of the shaft 55 is provided with an eX- pansion sleeve 57 by means of which the shaft 55 may be drivingly connected to rotate the tubular drive shaft 36.

The pot chuck 17 (Fig. 2) is provided with half bearing 60 which serves to support and locate the left hand end of a crankshaft to be ground. A clamping jaw 61 is pivotally mounted on the pot chuck and is arranged to 3 be actuated by means of a cylinder 62 and a piston 63 (Fig. ll) carried by the pot chuck 17. The piston 63 is connected by means of a piston rod 64 with a downwardly projecting portion of the clamping jaw 61. A compression spring 65 normally serves to hold the piston 63 in a left hand end position (Fig. 11). When fluid under pressure is passed through a pipe 66, through a passage 67 into a cylinder chamber 68, the piston 63 will be moved toward. the right to rock the clamping jaw 61 in a counterclockwise direction to clamp the left hand end of a crankshaft in position on the bearings 60 of the pot chuck 17.

Similarly the pot chuck 18 is provided with a fixedly mounted half bearing 70 (Fig. ll) which serves as a support for the right hand end of a crankshaft to be ground. The pot chuck 18 is provided with a pivotally mounted clamping jaw 71 which is actuated by a cylinder 72 and a piston 73 carried by the pot chuck 13. The piston 73 is connected by a piston rod 74 with a downwardly extending projection of the clamping jaw 71. A compression spring 75 serves normally to hold the piston 73 in a right hand end position (Fig. 11). When fluid under pressure is passed through the pipe 66 and through a passage 77 into a cylinder chamber 78, the piston 73 will be moved toward the left (Fig. 11) to rock the clamping jaw 71 in a clockwise direction to clamp the right hand end of a crankshaft to be ground fixedly to the hearing 70 of the pot chuck 18.

A suitable traversing mechanism is provided for traversing the table 11 longitudinally relative to the base 10, either manually or by power, to facilitate positioning successive portion of the work piece to be ground relative to the grinding wheel to be hereinafter described. This mechanism may comprise a half nut 80 depending from the under side of the table 11. The half nut 30 meshes with or engages a rotatable feed screw 81 (Fig. 5) which is journalled in spaced anti-friction bearings 82, 83 and 84. The feed screw 81 is connected by universal driving connections 85 with a driven shaft 86 of a rotary type fluid motor 3'7. It will be readily apparent from the foregoing disclosure that rotation of the motor shaft 86 will be transmitted through the screw 81 and the nut 80 to impart a longitudinal transversing movement to the work table 11.

A manually operable mechanism is provided for actu' ating the feed screw 81 manually, when desired. The manually traversing mechanism is contained within a casing 90 fixedly mounted on the front of the machine base 10. A manually operable hand traverse wheel 91 is mounted on the right hand end of the rotatable shaft 92 (Fig. 4). The shaft 92 is journalled in spaced anti-friction bearings 93 and 94. A gear 95 is keyed on the shaft 92 and meshes with a gear 96 carried by a stud 96a. The gear 96 meshes with a gear 97 carried by a stud 97a. The gear 97 meshes with a gear 93 which is keyed onto a rotatable shaft 99. The shaft 99 is connected by a clutch 100 with a rotatable shaft 101. The shaft 101 is keyed within the hollow end of a rotatable shaft 102 which is journalled in spaced anti-friction bearings 103 and 194. The bearings 103 and 104 are fixedly supported relative to the base 10. The shaft 102 is provided with a spiral gear 105 which meshes with a spiral gear 106 which is keyed onto the feed screw shaft 81. It will be readily apparent from the foregoing disclosure that rotation of the hand traverse wheel 91 will be imparted through the gear mechanism above described to rotate the feed screw 81 and thereby to transmit a longitudinal traverse movement to the table 11. The direction of rotation of the manually operable traverse wheel 91 serves to determine the direction of movement of the table 11. The base 10 also serves as a support for a transversely movable wheel slide 110 which is arranged to slide transversely on a flat Way and a V-way (not shown) formed on the upper surface of base 19. The wheel slide 110 rotatably supports a wheel spindle 111 which is journalled in suitable bearings (not shown). The wheel spindle 111 supports a grinding wheel 112 at its left hand end (Fig. l).

A suitable driving mechanism is provided for rotating the wheel spindle 111 and the grinding wheel 112. This mechanism may comprise an electric motor 113 which is mounted on an adjustable motor platen 114 which is arranged to be adjusted transversely relative to the wheel slide 110 by means of a manually operable adjusting screw 115 to facilitate tensioning the driving belts. The motor 113 is provided with a motor shaft 116 having a multiple V-groove pulley 117 mounted on its right hand end (Fig. 1). The pulley 117 is connected by multiple V-belts 118 with a multiple V-grooved pulley 119 mounted on the right hand end of the Wheel spindle 111.

A feeding mechanism is provided for moving the wheel slide 110 transversely relative to the base 10. This mechanism may comprise a half nut depending from the under side of the Wheel slide 110 which meshes with or engages a rotatable feed screw 126. The left hand end of the feed screw 126 is slidably keyed within a rotatable sleeve 127 which is journalled in spaced anti-friction bearings 128 and 128.1. The right hand end of the feed screw 126 is journalled in anti-friction bearings 129 carried by a slidably mounted sleeve 130 which is arranged to slide within a cylindrical bore 131.

A manually operable mechanism is provided for actuating the feed screw 126 to facilitate a manual transverse feeding of the wheel slide 110, when desired. This mechanism is contained within a casing 132 fixedly mounted on the front of the machine base 14 A rotatable shaft 133 at the upper portion of the casing 132 supports a manually operable feed wheel 134. A gear 135 is also supported on the shaft 133 and is arranged to rotate with the hand wheel 134. The gear 135 meshes with a gear 136 carried by a shaft 137. The gear 136 meshes with a gear 138 mounted on the left hand end of a rotatable shaft 139'. The shaft 139 also is provided with a gear 140 which meshes with a gear 141 fixedly mounted on the left hand end of a rotatable shaft 142. The shaft 142 is connected by a sleeve 143 with a rotatable shaft 144. The shaft 144 is provided with a gear 145 which meshes with a gear 146 carried by a rotatable shaft 147. The gear 146 meshes with a gear 148 which is keyed onto the rotatable sleeve 127. It will be readily apparent from the foregoing disclosures that manual rotation of the feed wheel 134 will be imparted through the gear mechanism just described to impart a rotary motion to the feed screw 126 so as to cause a transverse feeding movement of the wheel slide 110. The direction of movement of the wheel slide 110 being determined by the di-- rection of rotation of the manually operable feed wheel 134.

A wheel positioning and feeding mechanism is provided for rapidly causing the grinding wheel 112 to approach or recede from the work piece being ground. The rapid positioning mechanism comprises a hydraulic cylinder 150 supported within the base 10. The cylinder 150 contains a slidably mounted piston 151 which is fixedly mounted to one end of a piston rod 152. The left hand end of the piston rod 152 is operatively connected to the slidably mounted sleeve 130.

A feed control valve 155 is provided for controlling the admission to and exhaust of fluid from the cylinder 150. The valve 155 is a piston type valve comprising a valve stem 156 having valve pistons 157, 153, 159, 160 and 161 formed integrally therewith. The feed control valve 155 is substantially the same as that shown in the U. S. patent to H. A. Silven No. 2,572,529 dated October 23, 1951, to which reference may be had for details of disclosure not contained herein. As shown in Fig. ll, fluid under pressure from a pipe 162 enters a valve chamber formed between the valve pistons 157 and 158 and passses through a passage 163 into a cylinder chamber 16 4 to cause the piston 151 to move toward the right (Figs. 2 and 11) into a rearward or inoperative position. Durgreases ing this movement of the piston, fluid within a cylinder chamber 165 will exhaust through a pipe 166 into a valve chamber located between the valve pistons 159 and and passes out through an exhaust pipe 167. A compression spring 168 serves normally to hold the valve stem 156 in a right hand end position. A solenoid S1 is provided which when energized serves to shift the valve stem 156 toward the left so that fluid under pressure passing through the pipe 162 enters a valve chamber located between the valve pistons 159 and 160 and passes through the pipe 166 into the cylinder chamber to move the piston 151, the feed screw 126 and the wheel slide 110 toward the left so that the grinding wheel 112 rapidly approaches the work piece to be ground. During this movement fluid within the cylinder chamber 162 may exhaust through the passage 163, into the valve chamber located between the valve pistons 157 and 158 and passes out through an exhaust pipe 169. After the piston 151 covers a port 170, fluid exhausts from the cylinder chamber 164 exhaust through a pipe 171 and through a throttle valve 172 into the passage 163. During the reverse movement of the piston, fluid passing through the passage 163 initially passes through a ball check valve 173 into the cylinder chamber 164. After the port is uncovered by movement of the piston 151 toward the right, fluid passing through the passage 163 may pass through the port 170 into the cylinder chamber 164 and may also pass through the ball check valve 173 and through the pipe 171 into the cylinder chamber 164. It will be readily apparent from the foregoing disclosure that by regulation of the throttle valve 172, the rapid ap proaching movement of the grinding wheel 111 may be slowed down before the piston 151 reaches the end of its forward stroke, that is, toward the left (Figs. 2 and 11).

A fluid system is provided for supplying fluid under pressure for the various actuating mechanisms of the machine. This system may comprise a motor driven fluid pump 174 which draws fluid through a pipe 175 from a reservoir 176. The pump 174 supplies fluid under pressure to the main fluid pressure pipe 177 which is connected to the various actuating mechanisms of the machine. An adjustable pressure relief valve 178 is connected to the pipe 177 to return excess fluid through a pipe 179 to facilitate maintaining the desired operating pressure within the fluid system.

When the grinding wheel 112 is moved to an extreme rearward or inoperative position, it is desirable to provide a suitable cushioning mechanism to retard the rapid rearward movement of the piston 151 as it approaches the end of its rearward stroke. As shown in Figs. 2 and 11), the right hand end of the piston. rod 152 is arranged to engage the left hand end of a dash pot piston 180 which is slidably mounted within a dash pot cylinder 181 fixedly mounted on the right hand end of the cylinder 150. Fluid within a dash pot cylinder chamber 182 is exhausted through a pipe 183 and through a throttle valve 184 into the pipe 166. A compression spring 186 is provided normally to urge the dash pot piston 180 toward the left (Figs. 2 and 11). A ball check valve serves to prevent fluid exhausting from the dash pot cylinder chamber 182 into the cylinder chamber 165. When fluid under pressure is passed through the pipe 166 into the cylinder chamber 165 to cause the piston 151 to move toward the left, fluid under pressure may also pass through the ball check valve 185 and through the throttle valve 184, through the pipe 183 into the dash pot cylinder chamber 182 to return the dash pot piston toward the left into its initial position. v

A feeding mechanism is provided for producing a slow precise feeding movement of the grinding wheel during a grinding operation. In the preferred form, a hydraulically operated mechanism is provided for rotating the feed s'crew' 126 continuously for a plunge-cut grinding operation'. This hydraulic mechanism may comprise a cylinder 190 (Fig. 11) which contains a slidably mounted piston 191. A rack bar 192 is formed integral with the piston 191 and meshes with a gear 193 rotatably sup: ported on a shaft 194. The shaft 194 also supports a gear 138 which meshes with the gear 135 which is arranged to be turned by the manually operable feed wheel 134. When fluid under pressure is passed through a pipe 195 into a cylinder chamber 196 to cause the piston 191 to move toward the left, motion is transmitted through the gear 193, the gear 140, the gear 141, the shaft 142-144, the gear 145, the gear 146 andthe gear 148 to impart a rotary motion to the feed screw 126. This movement also causes the feed wheel 134 to rotate in a counterclockwise direction and serves to cause a forward infeeding movement of the wheel slide 110 and the grinding wheel 112. The infeeding movement continues until an adjustable stop abutment 197 carried by the feed wheel 134 moves into engagement with the end of a pivotally mounted stop pawl 198. The stop pawl 198 is pivotally supported by a stud 199 on the front of the machine base 10. During movement of the piston 191 toward the left, fluid within a cylinder chamber 196 formed at the left hand end of the cylinder 190 may exhaust through a pipe 201.

Similarly when fluid under pressure is reversed and passed through the pipe 201 into the cylinder chamber 200, the piston 191 will be moved toward the right (Figs. 2 and 11) so as to cause a clockwise movement of the feed wheel 134 and also to rotate the feed screw 126 so as to back off the grinding wheel 112 from the surface being ground.

In a crankpin grinding operation, it is desirable to provide means for slowing down the rapid approaching movement of the grinding wheel to a shoulder grinding feed which continues until the grinding wheel 112 is about to engage the body portion of the pin to be ground. The wheel feed is then slowed down to a predetermined body grinding feed which continue-s until the cylindrical portion of the crankpin being ground has been ground to approximate size at which time the wheel feed is again slowed down to a predetermined sizing feed. In order to accomplish this result, a control valve 205 is provided having a valve stem 206 which is provided with integral spaced valve pistons 207 and 208 forming a valve chamber 209 therebetween. In the position of the valve 205 (Fig. 11) fluid under pressure exhausting from the cylinder chamber 164 passes through the pipe 169 into the valve chamber 209 and out through an exhaust pipe 211 into the fluid reservoir to be hereinafter described. A com pression spring 210 normally serves to hold the valve stem 206 in a right hand end position. During the rapid approaching movement of the wheel slide 110 toward the left (Fig. 11) a lug 212 carried by the wheel slide 110 engages the valve stem 206 and moves it toward the left so that the valve piston 207 cuts off exhaust of fluid through the pipe 211. During the movement of the valve stem 206 toward the left, the piston 208 uncovers a port at the end of the pipe 213 so that fluid exhausting through the valve chamber 209 may pass out through the pipe 213 and through a shoulder feed throttle valve 214. Fluid exhausting through the valve 214 passes through the pipe 215, through the feed control valve 155 and out through the exhaust pipe 167. It will be readily apparent from the foregoing disclosure that by manipulation of the throttlevalve 214, the desired rate of shoulder feed of the grinding wheel 112 may be obtained.

It is desirable that the backlash in the feeding mechanism be rapidly taken up when the said feeding movement of the grinding wheel is started by rotation of the feed screw 126. This is preferably accomplished by means of a shuttle-type backlash control valve 216. This valve contains a slidably mounted valve member comprising a valve piston 217 and a valve piston 218 forming a valve chamber 219 thereb etween. In the position of the valve 216 (Fig. 11) fluid exhausting from the said cylinder chamber 200 through the pipe 201 is blocked by the vane piston 218. 7 When fluid under pressure is passed through the pipe 195 to initiate an infeedi'ng movement bribe piston 191', fluid from the pi'pe 195 also enters a valve chamber 221 formed at the left hand end of the backlash control valve 216 $6 as to cause the valve pistons 217 -218 to move toward the right. During movement of the vdlv e pistoiis 217-218 toward the right fluid in a valve chamber 222 is forced out through a pipe 223 an tln-tiug lia throttle valve 224. n will be; readily app'arent that by adjustment of the throttle valv'e 224, the ratebf movement of the valve pistons 21 7'2 18 may be readily controlled. As the valve chamber 219 passes acrosstli'e end of the pipe 201, fluid from the chamber 2ll0 ekhausting through the pipe 291 may pass substantially unrestricted through the valve chamber 219 and out through an exhaust pipe 229 into the reservoir. The unre'stricted exhaust of fluid from the chamber 238 allows the piston 191th moverapidly thereby taking up any backlash between the gears and the feed screw and nut. A check valve 225 allows fluid to bypass the throttle valve 224 when the direction of fluid under pressure to the backlash valve 216 is reversed.

The movement of the wheel slide llll at a shoulder grinding feed continues until the grinding wheel 112 is about to engage the peripheral portion of the crankpin to be ground. At this time an adjustable dog 228 carried by the wheel slide 110 closes a normally opened limit switch LS2 to energize a solenoid S4 to actuate a control valve 231. The control valve 231 is a piston type control valve having a slidably mounted valve member formed with integral valve pistons 232 and 233 forming a valve chamber 234 therebetw'ec'n. A compression spring 235 normally holds the valve pistons 232- 233 in a left hand end position so that the valve piston 233 covers a port at the end of a pipe 236. When the solenoid S4 is energized fluid exhausting from the feed cylinder chamber 208 through the pipe 201 passes through a pipe 237 into the valve chamber 234, through the pipe 236 and through a body feed throttle valve 238 which is connected to exhaust fluid through the pipe 215. It will be readily apparent from the foregoing disclosure that by manipulation of the throttle valve 230, the rate of the body infeed of the grinding wheel 112 may be varied as desired.

It is desirable to provide a slower or sizing feed which preferably is rendered operative when the crankpin has been ground to approximate size. The sizing feed is preferably obtained by means of a control valve 240. The control valve 240 is a piston type valve having a slidably mounted valve member formed with integral valve pistons 241 and 242 forming a valve chamber 243 therebet'w'een. A compression spring 244 serves normally to hold the valve pistons 241-242 in a left hand end position. In the position shown in Fig. 11 fluid exhausting into the valve chamber 243 may pass through the pipe i A solenoid S6 is provided which when energized serves to shift the valve pistons 241242 toward the right so thatthe valve piston 241 covers the port at the end of the pipe 237. At the same time the piston242 uncovers a port at the end of a pipe 245 so that fluid exhausting into the valve chamber 243 may pass through the pipe245and through a sizing feed throttle vane 246 into the exhaust pipe 215. n will be readily apparent from the foregoing disclosure that by manipulation of the throttle valve 2'46, the rate of sizing feed may be readily controlled. Closing a normally opened limit switch LS4 serves to energize the solenoid S6. The limit switch 154 is actuated by the feed stop pawl 198. When the feed wheel 134 moves in a. counterclockwise direction, a earn 247 on the stop abutment 197 will engage a cam surface formed on the end of the stop pawl 198 and serves to locate the stop pawl .198 in a counterclockwise direction thereby allowing the limit switch LS4 to close so as to energize the solenoid S6 thereby changing the rate of infeed of the grinding wheel 112 from a body f'eedto a sizing 'feed.

Aw'orl; steady rest 255 is provided for steadying a crankpin 254 during the sizing feed (Fig. 6). p The steady rest 255 comprises a steady rest base 256 which is clamped onto the upper surface of the swivel table 14. The steady rest base 256 supports a pivotally mounted frame 257 on a pivot stud 258. The frame 257 is provided with a horizontally movable work steadying shoe 259 which is arranged for a horizontal adjustment by means of an adjusting screw mechanism 260. The steady rest frame 257 also supp'ortsa lower steady rest shoe 261 which is mounted on a rock arm 262 which is pivotally connected to the frame 257 by a stud 263. An adjusting screw mechanism 264 is provided for adjusting eam 265 horizontally. The cam 265 engages a roller 266 carried by the rock arm 262. It will be readily apparent from the foregoing disclosure that by manipulation of the adjusting screws 260 and 264, the work steadying shoes 259 and 261 may be manually adjusted as desired. This steady rest is substantially the same as that shown in the prior U. S. patent to H. S. Silven, No. 2,419,170 dated April 15, 1947, to which reference may be had for details of disclosure not contained herein.

It is desirable to provide means for automatically actuating the screw mechanisms 260 and 264. Such mechanism may comprise a pinion 270 formed on the adjusting screw 268. The pinion 270 meshes with a vertically arranged rack bar 271. A compression spring 272 normally urges the rack bar 271 in a downward direction to impart a clockwise rotation to the pinion 270 and to the adjusting screw 260 so as to advance the steadyrest shoe 259 toward the crankpin 254 being ground. When fluid under pressure is passed through a pipe 273 into a cylinder chamber 274 formed in the lower end of a cylinder 275, a piston 276 contained within the cylinder 275 together with a piston rod 277 will be moved upwardly against the compression of the spring 272 to cause an upward movement of the rack bar 271 to rotate the pinion 270 and the adjusting screw 260 in a counter clockwise direction thereby retracting the shoe 259 from engagement with the work piece.

Similarly the adjusting screw 264 is provided with a pinion 280 which meshes with a vertically arranged rack bar 281. A compression spring 282 normally serves to exert force tending to move the rack bar 281 upwardly to impart a clockwise rotation to the pinion 280 and the adjusting screw 268 so as to advance the lower steady rest shoe 261 toward the work piece being ground. When fluid under pressure is passed through a pipe 283 into a cylinder chamber 284 formed at the upper end of a cylinder285, a piston 286 contained within the cylinder 285 together with a piston rod 287 will be moved downwardly against the compression of the spring 282 so as to cause a downward movement of the rack bar 281 thereby imparting a counterclockwise rotation to the pinion 280 and the adjusting screw 264 so as to withdraw the steady rest 261 from engagement with the work piece being ground. v

A pair of adjusting screws 278 and 279 are provided for limiting the movement of the rack bar 271 in either direc'tion. Similarly a pair of stop screws 288 and 289 are provided to limit the 'rnovement of the rack bar 281 in either direction.

It is desirable "to provide suitable mechanism for swinging the steady rest 'frame 257 about its pivot stud 258 to move the steady rest to an inoperative position so as to facilitate a longitudinal indexing movement of the work table 11. A hydraulically operated mechanism is provided for'moving the steady rest frame 257 to and from an operative position. This mechanism may comprise a cylinder 290 fixedlymo'unt'ed on the front of the tachine base. The cylinder 290 contains a slidably mounted piston 291 which is connected to the lower end of a piston rod 292. The piston rod 292 is a'rranged to engage the left 'handyenfd of a; rock arm 293 'which is pivotally supported by a stud 294 on the steady 'r'e'st base 256. The right hand end of the rock arm 293 is connected by a stud 295 with the upper end of a link 296 (Fig. 6). The lower end of link 296 is connected by a stud 297 with the left hand end of a rock arm 298. The rock arm 298 is pivotally supported by a stud 299 carried by the steady rest base 256. The right hand end of the rock arm 298 is provided with a roller 300 which is arranged to engage a cam surface 301 on a rock arm 302. The rock arm 302 is pivotally mounted on a stud 303. The upper end of the rock arm 302 is provided with a roller 304 which is arranged to engage a surface 305 formed on the under side of the steady rest frame 257. A spring 306 mounted on the steady-rest base 256 engages a pin 307 carried by the rock arm 302 and exerts a pressure tending to rock the rock arm 302 in a counterclockwise direction.

When fluid under pressure is passed through a pipe 308 into a cylinder chamber 309, the piston 291 will be moved upwardly thereby rocking the rock arms 293, 298 and 302 into the position illustrated in Fig. 6. During this movement fluid within a cylinder chamber 310 may exhaust through a pipe 311. When the flow of fluid is reversed so as to cause a downward movement of the piston 291, the rock arms 302, 298 and 293 will be rocked into the positions illustrated in Fig. 7 so as to allow the steady rest frame 257 to swing in a clockwise direction under the influence of gravity into a lower or inoperative position to facilitate a longitudinal traversing movement of the work table 11. This withdrawal of the steady rest frame 257 is necessary in a crank grinding operation in order to clear the adjacent arms of the crankshaft during the table indexing movement.

A solenoid-actuated valve 325 is provided for controlling the admission to and exhaust of fluid from the cylinder 290. The valve 325 is a shuttle-type valve having a slidably mounted valve member including integral spaced. valve pistons 326, 327, 328 and 329 forming valve chambers 332, 333 and 335 therebetween. The slidably mounted valve member is provided with a central passage 334. A pilot valve 330 is provided for controlling the shifting movement of the valve 325. The pilot valve 330 normally is held in a right hand end position by means of a compression spring and a solenoid S12 is provided which when energized serves to shift the pilot valve 330 toward the left thereby passing fluid into the left hand end chamber of the valve 325 to shift the slidably mounted valve member of the valve 325 toward the right. The valve 325 together with the pilot valve 330 and its actuating solenoid S12 is a standard commercial solenoid actuated valve such as for example that manufactured by Vickers Inc. of Detroit, Michigan. The pilot valve 330 serves to direct fluid under pressure to either one end or the other of the valve 325 to shuttle the valve 325 from one end position to the other. In the position shown in Fig. 11 fluid under pressure passing through the main pressure line 177 passes through a pipe 331 into the valve chamber 332 and through the pipe 311 to the cylinder 290 to cause a downward movement of the piston 291. During the downward movement of the piston 291, fluid within the lower cylinder chamber is exhausted through the pipe 308 into the valve chamber 333 through the central passage 334 into the valve chamber 335 and through an exhaust pipe 336 into the reservoir 176.

Similarly when the solenoid S12 is energized, the slidably mounted valve member of the valve 325 is shifted into a right hand end position so that fluid under pressure entering the valve chamber 332 passes through the pipe 308 into the cylinder chamber at the lower end of the cylinder 290 causing an upward movement of the piston 291 thereby swinging the steady rest frame 257 in .a counterclockwise direction into an operative position asshown in Fig. 6.

A solenoid-actuated control valve 315 is provided for controlling the admission to and exhaust of fluid from the cylinders 275 and 285. The valve 315 is a piston type valve having a slidably mounted valve member including integral spaced valve pistons 316, 317 and 318 which form valve chambers 319 and 320. A compression spring 321 serves normally to hold the valve member in a left hand end position. A solenoid S5 is provided which when energized serves to shift the slidably mounted valve member toward the right. In the position shown in Fig. 11, when fluid under pressure is supplied from the pipe 177 to a pipe 322, fluid enters the valve chamber 320 and passes through the pipe 273 and the pipe 283 into cylinder chambers 274 and 284 respectively to move the pistons 276 and 286 so as to retract the steady rest shoes 259 and 261 respectively. When the solenoid S5 is energized, the pipes 273 and 283 exhaust fluid from the cylinder chambers 274 and 275 respectively under the influence of the released compression in the springs 272 and 282 respectively into the valve chamber 319 and out through an exhaust pipe 323.

The steady rest shoes 259 and 261 respectively are maintained in an inoperative position and the infeed of the grinding wheel is changed from a body feed to a sizing feed at which time, it is desirable that the steady rest shoes automatically move into supporting engagement with the crankpin 254 being ground. This is preferably accomplished by means of a normally opened limit switch LS3 which is arranged to be closed simultaneously with the limit switch LS4 by the rocking movement of the feed stop pawl 198. As above explained, the closing of the limit switch LS4 serves to energize solenoid S6 thereby changing from a body grinding to a sizing feed. At the same time the closing of the limit switch LS3 energizes the solenoid S5 to shift the valve pistons 316-317318 toward the right so that fluid may exhaust from the cylinder chambers 274 and 284 respectively thereby releasing the compression of the springs 272 and 282 respectively. The released compression of the springs 272 and 282 re spectively serves to rotate the shoe adjusting screws 260 and 264 respectively so as to move the work steady shoes 259 and 261 respectively into operative engagement with the surface of the crankpin 254 being ground and to maintain them in supporting engagement therewith automatically as the crankpin is ground to size.

A control mechanism is provided for the table traverse motor 87 so that normally fluid under pressure may be passed to both sides of the motor. The rotation of the motor for traversing the table is accomplished by allowing fluid to exhaust from one side or the other of the fluid motor 87. As illustrated in Fig. 11 a table traverse control valve 340 is provided for controlling the admission to and exhaust of fluid from the fluid motor 87. The control valve 340 is a shuttle type valve having a slidable valve member formed with integral spaced valve pistons 341, 342, 343 and 344 forming a plurality of valve chambers 345, 346 and 347 therebetween. The slidably mounted valve member is provided with a central passage 348. A solenoid-actuated pilot valve 349 is provided for controlling the shifting movement of the valve 340. The

valve 340 is normally held in a central position by balanced springs. A pair of solenoids S7 and S8 are provided for shifting the pilot valve 349 so as to shift the valve 340 in either direction to cause a traversing movement of the work table 11. 1

As illustrated in Fig. 11 fluid under pressure from the pipe 177 enters the valve chamber 345 and passes through a pair of pipes 350 and 351 to the opposite sides of the fluid motor 87 thus providing a balanced pressure to hold the motor rotor stationary. When the solenoid S7 is energized, the pilot valve 349 is shifted toward the left so that the valve 340 is shiftedtoward the right. In this position of the valve 340 fluid may exhaust from the pipe 350 into the valve chamber 346 and out through an exhaust pipe 352. The exhaust of fluid from the pipe 350 unbalances the pressure to the motor 87 so that the motor 87 starts rotating the traverse screw 81 to traverse the work table 11 in one direction.

Similarly when the solenoid S8 is energized, the pilot 11 valve 491's shifted toward the right thereby shifting the valve 340 toward the left so that fluid may exhaust from thepip'e 351 into the valve chamber 347, through the cen tral passage 248 into the valve chamber 34-6 and exhausts through the pipe 352 so as to start rotation of the fluid motor 87 in the reverse direction thereby causing a trave'rsing movement of the table 11 in the opposite direction.

In the grinding of pins on a crankshaft it is necessary to traverse the table 11 through an idle stroke in indexing successive crankpins into operative relation with the grinding wheel. It is desirable to provide means whereby the traversing movement may be rapid so as to reduce the index time to a minimum. As illustrated in drawings a control is provided whereby the table 11 may be traversed rapidly and then automatically slowed down just before the next crankpin reaches an operative position. This is preferably accomplished by controlling the rate of exhaust of fluid through the pipe 352. A table speed control valve 355 is provided. The valve 355 is a shuttle type valve having slid'ably mounted valve member formed with integral valve pistons 356, 357, 358 and 359 forming a plur'ality of valve chambers 360, 361 and 362. A solenoidactuated pilot valve 364 is provided for controlling the shifting movement of the valve 355. As in the position illustrated in Fig. 11 fluid under pressure exhausting through the pipe 352 enters the valve chamber 360 and passes outthrough a pipe 363, through a slow speed throttle valve 365 and through an exhaust pipe 366. It will be readily apparent from the foregoing disclosure that by manipulation of the throttle valve 365, the rate of slow traverse may be varied as desired.

When a rapid traverse is desired, a solenoid S9 is energized to shift the pilot valve 364 toward the left thereby shifting the control valve 355 toward the right so that fluid exhausting from the pipe 352 enters the valve chamber 360 and passes out through a pipe 367 and through a rapid traverse throttle valve 368 into the exhaust pipe 366. It will be readily apparent from the foregoing disclosure that by manipulation of the rapid traverse throttle valve 368, the rapid traversing movement of the table 11 may be varied as desired.

A manually operable table traverse control lever 370 is pivotally mounted on a stud 371. The control lever 370 is arranged so that when rocked in either direction will close the normally opened limit switch LS6 or the limit switch LS7 to energize either the solenoid S7 or the solenoid S8 so as to shift the valve 340 to start the table 11 traversing in either direction. The speed of movement of the table will be determined by the position of the valve 355 which controls the rate of exhaust of fluid from the table traverse motor 87 either by the slow traverse throttle valve 365 or the rapid traverse throttle valve 368. The control lever 370 is also provided with a vertical plunger or push button 372 which is arranged to actuate a limit switch LS8. The limit switch LS8 is provided with a normally open and a normally closed contactor. As illustrated in Fig. '11 the upper contactor is normally closed so that when current is on the solenoid S will be energized. The lower contactor is normally open. When the push button 372 is pushed downwardly,

the upper contactor is opened and the lower contactor is closed to energize the solenoid S9 thereby shifting the pilot valve 364 toward the left to shift the valve 355 toward the right so that fluid exhausting from the motor 87 through the pipe 352 will pass through the rapid traverse throttle valve 368.

A table positioning mechanism is provided for successively positioning the work table 11 in predetermined positions to position successive crankpins on a crankshaft being ground into operative position relative to the grinding wheel 1 12.. The table indexing mechanism may comprise a notch-index bar 375 which is fastened to the front edgeof the work table 1.1 (Fig. 4). The index bar 375 is provided with a plurality of spaced notches 376 which are spaced in accordance with the spacing of the crank- 12 pins on the shaft to be ground. Cam surfaces 377 and 378 (Fig. 11) are provided adjacent to the notches 376.

An index plunger 379 is preferably formed as the valve stem of a control valve 380 having valve pistons 381 and 382 formed integrally therewith. A valve chamber 383 is formed between the valve pistons 381 and 382. A compression spring 384 serves normally to hold the plunger 379 in operative engagement with one of the notches 376. Fluid under pressure is passed through a pipe 386 to a solenoid actuated control valve 390. The notches 376 are slightly wider than the plunger 379 so as to facilitate jogging the table 11 for sparksplitting when desired. The control valve 390 is a piston-type of valve having a slidably mounted valve stem formed with integral spaced valve pistons 391, 392 and 393 forming valve chambers 3 94 and 395 therebetween. A compression spring 396 normally serves to hold the valve in a left hand end position. A solenoid S10 is provided which when energized serves to shift the valve into a right hand end position. Fluid under pressure passing through the pipe 386 from the control valve passes through the valve chamber 394 and through a pipe 387 into a cylinder chamber 385 to cause the valve stem or index plunger 379 to move out of engagement with a notch 376. When the solenoid S10 is energized, fluid may exhaust from the cylinder chamber 385 under the influence of the released compression of the spring 384 through the pipe 387, through the chamber 397 and out through an exhaust pipe 388 into the reservoir 176.

Fluid exhausting from the table traversing motor 87 passing through either the slow traverse throttle valve 365 or the rapid traverse throttle valve 368 passes through the pipe 366 into the valve chamber 383. When the plunger 379 is out of engagement with the notch 376, fluid exhausting into the valve chamber 383 may pass through an exhaust pipe 389 into the reservoir 176.

As shown in the hydraulic and electric diagram in Fig. 11, the electric current is off from the various circuits and the fluid pump 174 is idle. When the machine is started, the electric current is turned on the fluid pump 174 started. The upper contactors of the limit switch LS8 being closed, the solenoid S10 is energized so that the index plunger 379 remains in the position illustrated in Fig. 11 in engagement with a notch 376. When it is desired to index the table 11 to the next grinding position, the push button 372 on the lever 370 is depressed thereby actuating the limit switch LS8 to de-energize solenoid Sit) so that fluid under pressure enters the valve chamber 385 to remove the index plunger 379 from a notch 376. At the same time, the normally opened contactors of the limit switch LS8 close to energize the solenoid S9 thereby shifting the valve 355 so that fluid exhausting from the motor 87 through the pipe 352 will pass through the rapid traverse throttle valve 368. In this condition of the parts the lever 370 is rocked either toward the right or toward the left depending upon the desired direction of movement of the table 11. The rocking of the lever 37 0 serves through the limit switches LS6 and LS7 to energize either the solenoid S7 or S8 to shift the valve 340 to allow fluid to exhaust from one side of the motor 87 thereby starting rotation of the feed screw 81 and a longitudinal traversing movement of the table 11.

As the next crankpin approaches an operative position with relation to the grinding wheel 112, the operator releases the push button 372 thereby energizing the solenoid S'it: so that released compression of the spring 384 will move the index plunger into contact with the front edge of the index bar 379. As the index plunger 379 rides down the cam face 377, the valve piston 332 will move upwardly (Fig. 11) to gradually close the port at the end of the exhaust pipe 389 thereby gradually slowing down the traversing speed of the fluid motor 87 and the table 11. When the plunger 379 drops into 'a'n'ot'ch 376 duetoreleasedcompression'ot the spring 384 thevalve piston '38'2 co'mp'letely'covers the port at the end of the'pipc 13 389 thereby stopping the fluid motor 87 and the table 11 in the next index position.

It is desirable that the table traverse mechanism be rendered inoperative except when the grinding wheel 112 and the wheel slide 110 are in a rearward or inoperative position. This is preferably accomplished by means of a normally opened limit switch LS which is connected in series with the limit switches LS6 and LS7. The limit switch LS10 is arranged to be automatically closed by an adjustable dog 398 carried by the wheel slide 110. The dog 398 is adjusted so that the limit switch LS10 closes when the grinding wheel slide 110 reaches a rearward position thereby rendering the circuit operative so that a traversing movement of the work table 11 may be obtained.

A manually operable control valve 400 is provided for actuating the work clamping jaws 61 and 71 respectively. The valve 400 is a piston type valve comprising a valve stem 401 having valve pistons 402 and 403 formed integrally therewith. The valve pistons 402 and 403 form a valve chamber 404 therebetween. Fluid under pressure from the main pressure pipe 177 passes through a pipe 405 to the valve 400. A pipe 407 connects the valve 400 with a clamping control valve 410 to be hereinafter described. In the position of the valve 400 (Fig. 11) fluid may exhaust through the pipe 407 into the valve chamber 404 and out through an exhaust pipe 406 into the reservoir 176. A manually operable control lever 408 is pivotally mounted on a stud 409 and is operatively connected to the valve stem 404. When it is desirable to clamp a crankshaft into the machine, the control lever 408 is rocked in a counterclockwise direction (Fig. 11) to shift the valve stem 401 toward the right so that fluid under pressure passing through the pipe 405 enters the valve chamber 404 and passes through the pipe 407 to the valve 410.

The valve 410 is a piston type valve having a valve chamber 411 which in the position illustrated allows fluid under pressure from the pipe 407 to pass through the valve chamber 411 and through the pipe 66 to cylinder chambers 68 and 78 respectively so as to actuate the clamping jaws 61 and 71 to clamp the opposite ends of a crankshaft in the pot chucks 17 and 18 respectively. Similarly when the control lever 408 is rocked in a clockwise direction to position the valve 400 as illustrated in Fig. 11, the released compression of the springs 65 and 75 respectively forces fluid from the cylinder chambers 68 and 78 respectively through the pipe 66, the valve chamber 411, the pipe 407, the valve chamber 404 and through the exhaust pipe 406 into the reservoir 76 thereby opening the clamping jaws 61 and 71 respectively.

A cycle control mechanism is provided for manually initiating a grinding cycle. This mechanism may comprise a cycle control lever 414 which is pivotally supported on a stud 415. The lever 414 is arranged when rocked in a counterclockwise direction to close a normally opened start switch 416, or when rocked in a clockwise direction to open a normally closed stop switch 417. The closing of the start switch 416 energizes a time delay relay 418 which may be any of the standard well known time delay relays, such as, for example the Microflex timer manufactured by the Signal Electric Corporation of Moline, Illinois. The energizing of the relay 418 serves to close a circuit so as to render a normally opened limit switch LS9 operative.

The limit switch LS9 is provided so that a grinding cycle cannot be started unless a crankpin to be ground is in an operative position and clamped in the pot chucks 17 and 18 respectively. The limit switch LS9 is preferably actuated by a work engaging shoe 419 which is mounted on a rock arm 420 (Fig. 6). v The rock arm 420 is pivotally mounted on a stud 421 carried by the steady rest frame 257. The rock arm 420 is connected by a stud 422 with a link 423. The link 423 is connected by a stud 424 with the actuating arm 425 of the limit switch LS9. vWhen a crankshaft is in an operative position, a crankpin 254 will engage the shoe 419 and through the mechanism above described close the limit switch LS9.

The closing of the limit switch LS9 serves to energize a solenoid S2 (Fig. 11) which is operatively connected to rock a rock arm426 about its supporting stud 427 so that the roller 428 is rocked out of engagement with a depression formed in a work stop cam 429. The rocking of the rock arm 426 in a clockwise direction serves to close a normally opened limit switch LS5 which closes a cir cuit thereby starting rotation of the work drive motor 46.

The clockwise rocking of the rock arm 426 also shifts the valve 410 downwardly so that fluid under pressure from the main pressure line 177 may pass through a ball check valve 430, through a pipe 431 into the valve chamber 411 and through the pipe 66 to hold both of the clamping jaws 61 and 71 in a clamped position.

The manual actuation of the valve 400 to clamp a crankshaft in an operative position passes fluid under pressure through the pipe 407 and through the valve 410 to actuate the clamping jaws, and also passes through the pipe 66 to actuate a normally open pressure switch 412 so as to close the circuit to energize the solenoid S1. When the grinding cycle is started and the circuit closed to energize the solenoid S2 to clamp a crankshaft in the pot chucks which in turn serves to actuate the limit switch LSSto start the work drive motor 46 and thereby start rotation of the crankshaft to be ground. The solenoid S1 is also energized due to the fact that the pressure switch 412 is now closed thereby starting a feeding cycle.

A selector switch 432 is provided in the work motor circuit so that the work motor 46 may be controlled in the manner above described, if desired, or the selector switch 432 may be shifted in a clockwise direction so as to render a jog switch 433 operative so that the work motor 46 may be jogged when desired to facilitate setting up the machine for a given grinding operation.

At the same time the timer 418 is energized, a circuit is closed to energize the solenoid S12 thereby shifting the pilot valve 330 so as to shift the valve 325 toward the right so that the fluid under pressure is passed through the pipe 308 to cause an upward movement of the piston 291 to raise the steady rest frame 257 into an operative position. The work steadying shoes 259 and 261 remain out of engagement with the work until the sizing feed is rendered operative, as above explained.

It is desirable that the manually operable traverse Wheel 91 be rendered inoperative during the normal grinding cycle of operation. When the fluid pump 174 is started to pass fluid under pressure through the pipe 177, through the pipe 162, through the valve 155, through the pipe 215 through a pipe 440 into a cylinder chamber 441 formed at the left hand end of a cylinder 442.. The cylinder 442 contains a slidably mounted piston 443 which is fixedly mounted to one end of a piston rod 444. When the piston rod 444 is moved toward the right, it serves to rock a rock arm 445 in a clockwise direction about its supporting stud 446 to disengage a clutch thereby rendering the manually operable traverse wheel inoperative. A tension spring 443 serves normally to exert a tension tending to hold the clutch 4.47 in engagement.

A clutch 450 is provided to facilitate declutching the manually operable feed wheel 134 from the power feeding mechanism. The clutch 450 is normally held in engagement by a compression spring 451. A rock arm 452 pivotally mounted on a stud 453 is provided for actuating the clutch 450. A cylinder 454 contains a slidably mounted piston 455 having a piston rod 456 which is arranged to engage the rock arm 452. Fluid under pressure from the main pipe line 177 may pass through a pipe 457 to a rotary control valve 458 which is actuated by a control lever 459. When it is desired to. disengage he clutch 450, ,the control lever 459 is moved in a clock wise direction into position 459a so that fluid under pressure from the pipe 457 may pass through a pipe 460 into 15 a cylinder chamber formed at the left hand end of the cylinder 454 to rock the rock arm 452 in a counterclockwise direction to disengage the clutch 450.

The operation of this improved crankpin grinding machine will be readily apparent from the foregoing disclosure. As shown in Fig. 11 the electric current is off from the control circuits and the fluid pump 174 is idle. In the starting up of the machine the electric power is first turned on and at the same time the fluid pump 174 started to supply fluid under pressure through the pipe 177 to the various mechanisms of the machine. When fluid under pressure is passed through the pipe 177 fluid flows through the pipe 440 into the cylinder 442 to shift the piston 443 toward the right thereby disengaging the clutch 100 to render the hand wheel 91 inoperative.

A crankshaft to be ground is then loaded into the machine with its opposite ends supported by the pot chucks 17 and 18 respectively. The lever 403 is then rocked in a counterclockwise direction to shift the valve 400 toward the right so as to pass fluid under pressure through the pipe 407, through the valve 410 and through the pipes 66 to the cylinder chambers 68 and 78 respectively so as to actuate the clamping jaws 61 and 71 respectively to clamp the crankshaft in operative position within the pot chucks 17 and 13. At the same time fluid under pressure passing through the pipe 66 closes the normally opened pressure switch 412 to render a circuit to the solenoid S1 operative.

The feed cycle control lever 414 is then rocked in a counterclockwise direction to close the normally opened start switch 416 so as to energize the time delay relay 418. Energizing the time relay 418 serves to energize the solenoid S12 so as to shift the valve 325 into a right hand end position thereby passing fluid under pressure through the pipe 308 to cause an upward movement of the piston 291 thereby swinging the steady rest frame 257 in a counterclockwise direction into an operative position as illustrated in Fig. 6. During the swinging movement of the steady rest frame 257 into an operative position, the contact shoe 261 engages the crankpin 254 to be ground, and through the rock arm 420, and the link 423, serves to close the normally opened limit switch LS9. The closing of the limit switch LS9 serves to energize the solenoid S2 so as to rock the rock arm 226 in a clockwise direction thereby closing the normally opened limit switch LS5. The closing of limit switch LS5 closes a circuit to start the work drive motor 46. At the same time the solenoid S2 is energized, the solenoid S1 is also energized to shift the feed control valve 155 toward the left (Figs. 2 and 11). Fluid under pressure from the main pressure pipe 177 passes through the pipe 162, through the valve 155 and into the cylinder chamber 165 to start a rapid movement of the piston 151 together with the wheel slide 110 and grinding wheel 112 toward an operative position. The shifting of the feed control valve 325 serves to allow fluid to exhaust from the cylinder 442 through the pipe 440 under the influence of the tension spring 448 so as to engage the clutch 447 thereby rendering the hand Wheel 91 operative to facilitate a spark splitting operation.

As the wheel slide moves forward rapidly, the dog 393 moves out of engagement with the normally open limit switch L310 so that the limit switch LS opens thereby breaking the circuit to the limit switches LS6 and LS7 so as to render the table traversing mechanism inoperative during an infeeding movement of the grinding wheel.

The shifting of the feed control valve 155 toward the left serves also to direct fluid under pressure through thepipe'195 into the left hand end chamber of the cylinder 190 to start the piston 191 moving toward the right. At the same time fluid under pressure is passed through the pipe 195 into the left hand end of the backlash valve 2'16'sothat the valve 216 moves toward the right ata ratecontrolled by the throttle valve 224. During the movementof the valve 216 toward the right, a predetermined quantity of fluid is metered through the chamber 219 of the valve 216 into the exhaust pipe 220 to facilitate an initial rapid movement of the piston 191 toward the right to take up backlash in the feed mechanism parts.

After a predetermined rapid approaching movement of the wheel slide 11%, a lug 212 engages the stern 206 of the valve 295 and shifts the valve toward the left so that fluid under pressure exhausting from the cylinder chamber 164 passes through the valve chamber 209, through the pipe 213 and out through the shoulder feed throttle valve 214. The rate of the shoulder feed may be readily regulated by manipulation of the throttle valve 214. After a predetermined shoulder feed, the dog 228 carried by the wheel slide engages and closes the normally opened limit switch LS2 to close a circuit thereby energizing the solenoid S4 to shift the valve 231 toward the right which serves to direct exhaust fluid from the feed cylinder 1% through the body feed throttle valve 230 which is rendered effective as the grinding Wheel is about to engage the peripheral portion of the crankpin 254 to be ground.

During the infeeding movement of the piston 191, the hand wheel 134 turns in a counterclockwise direction at a body feed speed. When the diameter of the crankpin being ground reaches a predetermined size, the normally opened limit switches LS4 and LS3 are closed. The closing of the limit switch LS4 serves to energize the solenoid S6 thereby shifting the valve 240 toward the right so that fluid exhausting from the cylinder 190 passes through the sizing feed throttle valve 246 which controls the rate of infeed during the sizing operation. At the same time, the normally opened limit switch LS3 is closed to energize the solenoid S5 which shifts the valve 315 toward the right so as to exhaust fluid to the cylinders 275 and 235 respectively thereby releasing the compression of the springs 272 and 282 respectively which serves to rotate the shoe adjusting screws 270 and 280 respectively in a counterclockwise direction to advance the steady rest shoes 259 and 261 into operative steadying engagement with the crankpin 254 to be ground. The compression of the springs 272 and 232 serves to maintain the steady rest shoes in supporting engagement with the crankpin being ground as it is reduced in size by the grinding operation.

When the time delay relay 418 times out the circuit is broken to deenergize the solenoid $12 so that the valve 325 returns to the position illustrated in Fig. 11 thereby admitting fluid under pressure to the upper end of the cylinder 2% to cause the steady rest frame 257 to swing in a clockwise direction to an inoperative position. At the same time when the timer times out, a circuit through the limit switch LS9 serves to deenergize the solenoids S2 and S1. The work motor continues to rotate the pot chucks until the roller 4-28 drops into the depression of the cam 429 at which time the released compression of the spring within the valve 410 rocks the rock arm 426 in a counterclockwise direction to open the limit switch LS5 thereby breaking the circuit to stop the work drive motor 46 with the pot chucks 17 and 18 in a predetermined upright position to facilitate either an indexing movement of the crankpin being ground or removal .of the crankshaft after the grinding operation has been completed.

The deenergizing of the solenoid S1 releases the compression of the spring 168 so that fluid under pressure is passed into the cylinder chamber 164 to cause a rearward movement of the piston 151, the wheel slide 110 and the grinding wheel 112 to a rearward or inoperative position. During the rearward movement of the wheel slide, the valve 205 resets due to the released compression of the spring 210-. The limit switch LS2 opens thereby decnergizing the solenoid S4 to facilitate resetting of the valve 231 by releasing the .compression of the spring 235. The latter movement of the feedcontrol valve serves to reset the cylinder 442, that is, to dis- 17 engage the clutch 100 and therefore render the hand wheel 91 inoperative. The piston 191 is also reset by passing of fluid under pressure through the pipe 201.

During movement of the piston 191 toward the left, the feed Wheel 134 is rotated in a clockwise direction and the limit switches LS4 and LS3 are opened. The opening of the limit switch LS4 serves to deenergize the solenoid S6 thereby resetting the valve 240. The opening of the limit switch LS3 serves to deenergize the solenoid S5 resetting the valve 315 so that fluid under pressure is passed to the cylinders 275 and 285 to retract the steady rest shoes 259 and 261 respectively to an inoperative position.

As the wheel slide 110 approaches its rearward or inoperative position, the dog 398 engages and closes the normally open limit switch LS thereby closing a circuit to render the limit switches LS6 and LS7 operative thereby permitting a traversing movement or indexing movement of the work table 11.

When the solenoid S2 is deenergized and the rock arm 426 is swung in a counterclockwise direction, the roller 328 moves into engagement with the periphery of the cam 429. When the cam 429 rotates so that the roller 428 drops into a depression in the cam, the valve 410 moves upwardly thereby cutting off fluid under pressure through the pipe 431 and passes pressure from the pipe 407 to the clamping cylinders 62 and 72 respectively.

The crankshaft may then be indexed by the actuation of the lever 408 to release the clamping jaws 61 and 71 after which the crankshaft may be rotated to position the next crankpin to be ground into axial alignment with the axis rotation of the work spindles and 30 respectively.

The table 11 may be then indexed longitudinally by first depressing of the button 372 and then moving of the lever 370 either toward the right or toward the left depending upon the direction of movement of the table 11 desired. The depressing of the button 372 serves to actuate the limit switch LS8 so as to energize the solenoid S9 thereby shifting the valve 355 toward the right to render the rapid traverse throttle valve 368 operative. Actuation of the limit switch LS8 serves also to break a circuit thereby deenergizing the solenoid S10. Movement of the lever 370 toward the right or left closes either the limit switch LS7 or the limit switch LS6 to energize either the solenoid S8 or S7 thereby opening one side of the table traverse fluid motor 87 to the exhaust to facilitate a longitudinal movement of the table for positioning the next pin to be ground. The deenergizing of the solenoid S10 serves to shift the control valve 390 toward the left into the position illustrated in Fig. 11 so that fluid under pressure is passed through the pipe 387 into the cylinder chamber 385 to withdraw the plunger 379 from the notch 376 in the index bar 375. The table 11 moves rapidly during the positioning movement. As the next crankpin to be ground approaches a grinding position, the button 372 is released thereby returning the limit switch LS8 into the position illustrated in Fig. 11. This movement serves to deenergize the solenoid S9 so that the valve 355 returns to the position illustrated in Fig. 11 with the slow traverse throttle valve 365 controlling the rate offluid exhausting from the table traverse motor 87. At the same time the solenoid S10 is energized so that fluid may exhaust from the cylinder chamber 385 thereby releasing the compression of the spring 384 so that the plunger 379 engages the surface of the index bar 375. As the index plunger 376 rides up the cam face 377, the exhaust of fluid from the valve chamber 383 into the pipe 389 is gradually cut off thereby slowing down the rotation of the fluid motor 87 until the plunger 79 moves into engagement with notch 376 at which time the entire exhaust of fluid into the pipe 389 is cut off thereby stopping the fluid motor 87 with the work table 11 in posiion for grinding the next crankpin. This cycle of operation is continued until all of the crankpins on the shaft have been ground. After the last pin has been ground, the cycle control lever 414 is moved into the position illustrated in Fig. 11 and the lever 408 is also shifted back into the position illustrated in Fig. 11 so that fluid may exhaust from the clamp cylinders 62 and 72 respectively to unclamp the clamping jaws 61 and 71 respectively to facilitate removal of the ground crankshaft from the machine.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all material hereinbefore set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a crankpin grinding machine having a base, a longitudinally movable table thereon, means including a fluid motor to traverse said table, a solenoid-actuated reversing valve to control the direction of movement of the table, a manually operable control lever therefor, a pair of limit switches actuated by said lever for controlling the reversing valve, a transversely movable wheel slide on said base having a rotatable grinding wheel thereon, means including a piston and cylinder to move said slide in either direction, a solenoid-actuated control valve therefor, means including a manually operable control lever for controlling the latter valve, and an electrical interlock including a limit switch actuated by the forward movement of the wheel slide to render said limit switches inoperative during an infeeding movement of the wheel slide so as to render the table traverse motor inoperative during an infeeding movement of the wheel slide.

2. In a crankpin grinding machine having a base, a longitudinally movable table thereon, means including a fluid motor to traverse said table, a solenoid-actuated reversing valve to control the direction of movement of the table, a manually operable control lever therefor, 21 pair of normally open limit switches actuated by said lever for controlling the reversing valve, a transversely movable wheel slide of said base having a rotatable grinding wheel thereon, means including a piston and cylinder to move said slide in either direction, a solenoid-actuated control valve therefor, means including a manually operable control lever for controlling the latter valve, and a normally open limit switch which is opened by the forward movement of the wheel slide to render the pair of limit switches and the table traversing motor inoperative during a transverse infeeding movement of the wheel slide.

3. In a crankpin grinding machine having a base, a longitudinally movable table thereon, means including a fiuid motor to traverse said table longitudinally, a solenoid-actuated reversing valve to control the direction of movement of the table, a manually operable control lever therefor, a pair of limit switches actuated by said lever for controlling the reversing valve, a transversely movable wheel slide on said base having a rotatable grinding wheel thereon, means including a piston and cylinder to move said slide in either direction, a solenoid actuated control valve therefor, means including a manually operable control lever for controlling said latter valve, an adjustable dog movable with said wheel slide, and a limit switch which is actuated by said dog when the wheel slide moves into an inoperative position to render said table traverse mechanism operative only when wheel slide is in an inoperative position.

4. In a crankpin grinding machine having a base, a longitudinally movable table thereon, means including a fluid motor to traverse table longitudinally, a solenoidactuated reversing valve to control the direction of movement of the table, a manually operable control lever therefor, a pair of limit switches actuated by said lever for controlling the reverse valve, a transversely movable wheel slide on said base having a rotatable grinding wheel thereon, means including a piston and cylinder to move said slide in either direction so as to cause a rapid approaching and receding movement of said slide, a solenoid-actuated control valve therefor, means including a nut and screw said mechanism interposed between said piston and wheel slide, means including a piston and cylinder to rotate said screw so as to impart a feeding movement to said slide, means including a manually operable lever for controlling saidlatter valve, an adjustable dog movable with the wheel slide, and a normally open limit switch which is closed by said dog when the wheel slide is moved into a rearward inoperative position to close a circuit to render said pair of limit switches operative so as to render the table traverse mechanism operative only when the wheel slide is in a rearward position.

5. In a crankpin grinding machine having a base, a longitudinally traversable table thereon, means including a fluid motor to traverse said table longitudinally in either direction, a fluid actuated reversing valve, operative con nections between said valve and said motor arranged normally to pass fluid under pressure to both sides of the fluid motor, a pilot valve for shifting said reversing valve, a pair of independent solenoids to shift said pilot valve in either direction to shift said reversing valve so as to facilitate exhaust of fluid from one side of said motor, a manually operable control lever therefor, and a pair of limit switches each of which is operatively connected to actuate one of the said solenoids, said limit switches being arranged to be actuated by movement of said lever so as to control the direction of movement of the table.

6. In a crankpin grinding machine having a base, a longitudinally traversable table thereon, means including a nut and screw mechanism operatively connected to traverse said table, means including a fluid motor to rotate said screw, a solenoid-actuated reversing valve, operative connections between said valve and motor normally to pass fluid under pressure to both sides of said motor, an independent solenoid to shift said valve in either direction 50 as to facilitate exhaust of fluid from one side of said motor, a manually operable control lever therefor, and a pair of limit switches each of which is operatively connected to actuate one of said solenoids, said limit switch being arranged to be actuated by movement of said lever so as to control the direction of movement of the table.

7. In a crankpin grinding machine, as claimed in claim 5, in combination with the parts and features therein specified of a slow traverse and a rapid traverse throttle valve to control the exhaust of fluid from said motor, a solenoid-actuated control valve operatively connected between the reversing valve and said throttle valves to render one of said throttle valves inoperative, and a manually operable switch on said control lever to actuate said control valve to cause either a slow or a rapid traversing movement of the table when desired.

8. In a crankpin grinding machine, as claimed in claim 5, in combination with the parts and features therein specified of an independent slow speed and arapid speed throttle valve to control the exhaust of fluid from said motor, a solenoid-actuated control valve operatively connected between the reversing valve and said throttle valves to render one of said throttle valves inoperative, said control valve being arranged normally to facilitate exhaust of fluid through the slow speed throttle valve, and a manually operable switch on said control leverto energize said control valve so as to render the rapid traverse valve operative to cause a rapid traversing movement of the table when desired.

9. In a crankpin grinding machine, as claimed in claim 4, in combination with the parts and features therein specified of a pair of spaced aligned rotatable pot chucks on said table each having a pivotally mounted work clamping jaw, a hydraulic piston and cylinder on each of said chucks for actuating said jaws, a solenoid-actuated control valve to control the admission to and exhaust of fluid from said cylinders, a work steady rest having movable steady rest shoes for steadying a work piece being ground, and a limit switch on said steady rest to energize said solenoid valve so as to actuate said clamping jaws only when a work piece is in operative position in said pot chucks.

, 10. In a crankpin grinding machine, as claimed in claim 4, in combination with the parts and features therein specified of a pair of spaced aligned rotatable pot chucks on said table each having a pivotally mounted work clamping jaw, a hydraulic piston and cylinder on each of said chucks for actuating said jaws, a solenoidactuated valve to control the admission to and exhaust of fluid from said cylinders, a work steady rest on said base having a pivotally mounted frame, a pair of movable work shoes on said frame for steadying a work piece being ground, a piston and cylinder to move said frame to and from an operative position, a solenoid-actuated control valve therefor, a piston and cylinder mechanism to move said shoes relative to said frame, a solenoidactuated control valve therefor, and a manually operable cycle control including an electric timer to control a. grinding cycle, said timer when energized being operatively connected to energize the second solenoid valve to move the steady rest frame to an operative position, said timer also serving to energize the solenoid feed control valve to start a grinding cycle, and a limit switch actuated by and in timed relation with the feeding mechanism to energize said third solenoid valve automatically to advance the steady rest shoes into operative engagement with the work piece being ground.

11. In a crankpin grinding machine, as claimed in claim 3, in combination with the parts and features therein specified of a pair of spaced aligned rotatable pot chucks for supporting and rotating a crankshaft to be ground, each of said chucks having a hydraulically actuated clamping jaw, a control valve operatively connected to control the actuation of said clamping jaws, and means including a pressure-actuated switch in said operative connections to render said feed control valve operative only when a crankshaft is clamped in said pot chucks.

12. In a crankpin grinding machine, as claimed in claim 5, in combination with the parts and features therein specified of a table positioning mechanism including a notched bar on said table having a plurality of spaced notches, a slidably mounted index plunger on said base, said index plunger being arranged successively to engage said notches precisely to position the table in successive grinding positions, and a compression spring normally to maintain said plunger in engagement with one of said notches.

13. In a crankpin grinding machine, as claimed in claim 5, in combination with the parts and features therein specified of a table positioning mechanism in cluding a notched bar on said table having a plurality of spaced notches, an index control valve on said base including a slidably mounted valve member, an index plunger formed integral with said valve member, said plunger being arranged successively to engage the notches on said bar precisely to position the table in predetermined indexed positions, a compression spring normally to hold said plunger in engagement with the surface of said bar or one of said notches, said index control valve being operatively connected to control the exhaust of fluid from the table traverse motor, and a cam surface on said bar adjacent to each of said notches to facilitate movement of said plunger as it approaches a notch gradually to cut off exhaust of fluid from the table motor so as to slow down the table movement as the table approaches an indexed position.

14. In a crankpin grinding machine, as claimed in claim 5, in combination with the parts and features therein specified of a table positioning mechanism including a notched index bar on said table having a plurality of spaced notches, an index control valve on said base including a slidably mounted valve member, an index plunger formed integral with said valve member, said plunger being arranged successively to engage the notches on said bar precisely to position said table in predetermined index positions, a compression spring normally to hold said plunger in engagement with the surface of said index bar or one of said notches, said index control valve being operatively connected to control the exhaust of fluid from the table traverse motor, said control valve having a port which is gradually closed by movement of said bar, and a cam surface on said bar adjacent to each of said notches to facilitate movement of said plunger as it approaches a notch on said bar gradually to close said port so as to cut off exhaust of fluid from said motor thereby to slow down and stop the table movement when said plunger moves into engagement with one of said notches.

15. In a crankpin grinding machine as claimed in claim 5, in combination with the parts and features therein specified of an index control valve on said base including a slidably mounted valve member, an index plunger formed integrally with said valve member, said plunger being arranged successively to engage the notches on said bar precisely to position the table in predetermined indexed positions, a compression spring normally to hold said plunger in engagement with the surface of said index bar on one of said notches, an end chamber in said index control valve, means including a solenoid-actuated control valve to control the admission to and exhaust of fluid from said end chamber, said solenoid valve being normally energized so that the fluid may exhaust from said end chamber thereby releasing the compression from said spring to maintain the plunger in operative engagement With said index bar, and means including a limit switch on said reversing lever operatively connected to deenergize said solenoid actuated control valve to Withdraw said plunger to facilitate an indexing movement of the table.

References Cited in the file of this patent UNITED STATES PATENTS 1,882,098 Silven Oct. 11, 1932 2,117,916 Silven et al. May 17, 1938 2,142,050 Garside et al. Dec. 27, 1938 2,442,635 Bennett June 1, 1948 2,458,290 Monroe Jan. 4, 1949 2,460,744 Green Feb. 1, 1949 2,655,903 Tyler Oct. 20, 1953

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